The present invention relates to a method for optical inspection of gutted fish with opened abdominal cavity. The invention further relates to a method for gutting fish which are conveyed along a processing line in the longitudinal direction by means of a conveying device.
In addition, the invention relates to an apparatus for optical inspection of the opened abdominal cavity of gutted fish as well as an apparatus for gutting fish which are conveyed along a processing line in the longitudinal direction by means of a conveying device.
Such apparatuses and methods are used in industrial fish processing. The fish are usually automatically slaughtered by opening the abdominal cavity of the fish and automatically removing the guts thereof using appropriate tools. The gutting result is usually checked optically. For this, the abdominal cavity of the fish in inspected with a colour camera subsequent to the gutting step and the image taken of the abdominal cavity is examined for any possible remaining residues of blood and/or gut using known image processing algorithms.
These known apparatuses and methods have a number of disadvantages. Due to the use of a colour camera, which splits the incident light into each of the primary colours by means of a Bayer filter, the effective resolution is significantly reduced compared to a monochrome camera. On the other hand, correspondingly long exposure times are required. This is contrary to the requirement for the highest possible conveying speed of the fish because the maximum conveying speed is severely limited due to the exposure time to be observed. An increase in the conveying speed results in blurred images of the abdominal cavity and thus overall to lower reliability of the image evaluation. A further disadvantage is that evaluation of the colour images is computing- and time-intensive.